FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1919
1919 - 0144.PDF
JANUARY 30, 1919 AIRSHIPS FOR COMMERCIAL PURPOSES [ Officially issued by The Relative Advantages of Airships and Aeroplanes IN view of the different characteristics of airships and aero planes, it appears that the future uses of the two types for commercial purposes will not conflict. The airship is essen tially a long-distance weight-carrying craft as compared with the short-distance high-speed aeroplane. It should be noted, however, that even in the matter of speed the airship of to-day with a speed of 77.6 m.p.h. can be considered slow- only relatively to the aeroplane, as she is unquestionably fast in comparison with land and sea methods of transport. In addition to this the airship has the advantage of not being dependent upon her speed through the air for her ability to remain aloft, and is not, therefore, liable to forced descent in case of engine failure, as is the aeroplane. Quite large repairs to engines, such as the changing of a cylinder, are possible in an airship. The airship, then, is worthy of consideration for com mercial flights over sea or land of a wooded or broken nature, such as to be unsuitable for the landing of aeroplanes, and on journeys involving non-stop flights of 1,000 miles and upwards. In addition to this, airships are the most suitable aircraft for the carrying of passengers, where safety, comfort and reliability are essential.* An airship can remain aloft while engine repairs are effected ; she always remains on an even keel, and there is, therefore, no danger in flying at night or in fog or clouds, and the great lift permits of much more comfortable accommodation being provided than is possible in an aeroplane, there being room to move about. In the case of a rigid airship, for example, a walk of 400 or 500 ft. may be taken along the keel. The fact that the envelope is filled with an inflammable gas need not cause any misgivings as to safety, when one remembers the large number of motor vehicles which have been used during the War carrying bags filled with equally inflammable coal-gas at no greater distance from the engine than in the case of an airship. Official statistics show that only one airship has been lost in this country owing to catching fire in the air, although 83-360 hours have been flown and over 2,500,000 miles covered during the War. In the case referred to the flight was an experimental one with a new type of ship, and the cause has since been ascertained and eliminated. Conditions favourable to Airship Transport : Trans-oceanic Services.—It appears that for commercial purposes large rigid airship stations should be established at distances of 2,000 to 3,000 miles apart, mainly for trans-oceanic traffic, while the aeroplane would be used for bringing passengers and merchandise to these from the neighbouring countries. For example, a continental airship service could be run from Lisbon to New York, passengers being taken to Lisbon from Paris, Rome, etc., by aeroplane. In this way the aeroplane would compete with the train and the airship with the steam ship, over which she would have the advantage of reducing the average time of transit by at least 50 per cent. In addition to this airships would be used for Unking up the railways in such places as Central Africa, where the country is difficult both for aeroplanes and land transport. It is worthy of note that though airships are generally considered to be fair-weather craft, up to the end of Novem ber there were only nine days in 1918 when no airship flight took place in the British Isles—which are notorious for possessing almost the worst weather conditions of any country in the world. The airship is able to fly on days when fog or low-flying clouds are prevalent, which might be considered unsuitable for aeroplanes. In long voyages, advantage could be taken of favourable winds and the routes chosen accordingly. Owing to her long endurance, an airship could afford, should a depression be met with, to fly either over or round it. The latest German rigid airship has a disposable lift avail able for crew, fuel, merchandise, etc., of over 38 tons, which gives her a theoretical endurance (if all the available lift be employed in carrying petrol) of 177.5 hours (7 days) at a cruising speed of 45 m.p.h.—the maximum speed being 77.6 m.p.h.—during which 8,000 miles would be covered. A detailed statement of the " disposable lift " available for freight of each existing type of British airship showing the petrol consumption is attached. From these figures the freight which can be carried and the time taken over any given route can readily be worked out. The Advantages of Mooring Out Airships : Cheap Housing and Independence of Weather.~lt should be noted that for purposes of short distance pleasure trips from, for example, * Vide Report of Civil Aerial Traniport Committee. the Air Ministry.] South Coast towns, it would not be necessary to establish large stations at each town, but the following principle, which has been found most economical and successful during the War, might be adopted. This consists of building a station provided with permanent sheds, quarters, etc., at some convenient centre, and forming temporary bases con sisting merely of a small cheap portable shed and a few tents or huts at other places, from each of which one or two airships are run ; main supplies being drawn from the " parent " station where all large repairs are effected. In addition to the use of portable sheds at sub-stations, experiments have been carried out in mooring out airships in the open, which have had such a large measure of success as to promise well for the future. An airship has been successfully moored out for six weeks in a perfectly open expanse to a specially designed mast. Only two or three men are required to look after the ship, and winds of up to 52 m.p.h. have been ridden out without any damage whatever resulting. There seems little doubt that with this system an airship could live out in the open for many months at a time. Up to the present this method has only been tried with small non-rigid airships, but it is on the point of being tried with rigids, and there seems no reason to expect other than equal success. The possibilities of using floating sheds on water are also being enquired into, and appear to be promising. Improvements to Airships in the Immediate Future.— It should be noted generally that greater reliability as well as decreased cost will undoubtedly be attainable by improvements re sulting from careful research and experiment. For example, the use of a mooring mast will very greatly increase the regularity of any airship service, as the chief difficulty at present consists in taking airships in and out of sheds. If an airship is left permanently ready at a mooring mast in the open it will be possible to fly in any wind up to the speed of the ship. In the same way improvements in the fabric for non-rigid envelopes and outer covers of rigid airships will result in decrease in running costs by reducing the hydrogen consumption, and generally lengthening the life of the ship. Similarly, a system of recovering water-ballast during flight would obviate waste of hydrogen by preventing the ship becoming " light," owing to the consumption of fuel during a long voyage. It will be understood that as an airship becomes light she tends to rise, which causes the hydrogen to expand, so that it must be allowed to escape through the automatic valves, or the gas-bags would be burst by the internal pressure. This tendency to rise must be counter acted by taking in weight to counterbalance that lost in the fuel consumed. The Commercial and Technical Merits of Airships tn Com parison with Aeroplanes.—Two appendices are attached, giving respectively a technical comparison of the airship and the aeroplane for long-distance flying, and full details as to performance, cost, etc., of the various types of British airships, showing an estimate of the man-power required to run a commercial airship service. It may be of interest to note that nine airship stations of various sizes will in all probability shortly cease to be in use by the Admiralty. These will, therefore, become available for commercial purposes, though the greater part of the ground is occupied under the Defence of the Realm Act. In addition a certain number of S.S. Zero airships and costal star airships will become available for disposal. APPENDIX A The Development and Potentialities of Rigid Airships and Aeroplanes I. Foreword.—During the last four years sufficient ex perience has be n obtained in the constraction and use of rigid airships to enable future developments to be forecasted with some assurance of accuracy ; and it is, therefore, possible to consider the fines along which progress should be sought, and the performances which, within the next few years, can be obtained from rigid airships. In view of the widely-held opinion that the development of the large aeroplane will ultimately kill the large airship, it is necessary to institute a comparison between the future possibilities of both types. The result shows that in each case certain inherent qualities govern progress, and that these qualities, being widely differ ent, will cause the two types to cover different fields of utility. It appears also that, whereas increase in size of aeroplanes brings many difficulties in its train with no compensating improvement in efficiency, increase in size of airships results in a reduction of the difficulties experienced at present, and
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
